Sheet feeding device for cylinder printing presses



R. STUSSI W SHEET FEEDING DEVICE FOR CYLINDER PRINTING PRESSES Filed Jan. 31, 1934 2 Sheets-Sheet 1 ynvenwr Rudolf $566556 Emily Q1935. I R. STUSSI WZfi SHEETFEEDING DEVICE FOR CYLINDER PRINTING PRESSES Filed Jan. 51, 1934 2 Sheets-Sheet 2 Jnventor 5 Patented July 9, 1935 actress PATENT oFFIcE sneer FEEDING nnvron FOR CYLINDER rarN'rrNe ranssns Rudolf Stiissi, Glarus, Switzerland,

Druckmaschinen Switzerland assignor to Aktiengesellschaft, Glarus,

Application January 21, 1934, Serial No. 709,207 In Germany February 6, 1933 4 Claims. (o1. 271-52) This invention relates to a sheet feeding device, or sheet-supplying devicerespectively, for cylinder printing presses. The invention is intended for use in connection with cylinder printing presses in which the sheets are individually taken away from a pile, and led to laying-on marks. 7 It has already been proposed to convey the over a laying-on table sheets over the laying-ontable by means of reciprocating sucking members arranged below said table, but the knownfconstructional forms of the devices of that type" suffer from the considerable drawback that when working diiierent sorts of paper, for instance undulated'sheets, disturbances arise, in that fresh air finds access into the sucking members. Another drawback of those known constructional forms when being used for .feeding the sheets resides therein. that there arise differences in the position of the individually supplied sheets which necessitates the provision of specialmeans for making each sheet contact properly at its front edge with the laying-on marks. Also the employment of sucking devices entails the disadvantage that two air pumps with 25 drop or poppet valve gears and with the requisite suction pipes become necessary whereby the costprice of the machine is increased.

I am also aware of constructional forms in which pressing cushions for. holding the sheets are attached to continually running. endless chains, but these devices render necessary the provision of chains with cushions above the laying-on table, as well as below the same, the

arrangement being such that the sheet is taken hold of by two cushions, that is to say, between the same whereby the draw-back is entailed that the space above the laying-on table is rendered inaccessible by the chains so that laying-on the l sheets also by hand is rendered impossible. It

overcome by the present improved constructional 7 form, the gist of which resides therein that grippers are. used which seize the sheet, at its front edge. and "are operated by means located below the laying-on table, the arrangement being such thats'aid grippers extend upwardly. through slots of the'laying-on table as long. as they convey the sheet, but at the end of this path they are withdrawn downwardly, away from said table. Closing the said grippers at the commencement of their conveying path and opening them at the end of that path is likewise effected by means located below the laying-on table, these means being so designed that the closing and opening takes place with absolute exactness andreliability, and the sheets are conveyed along over said table with the greatest precision. A particular advantage is, finally, this, that the place above the laying-on table-is and remains freely accessible so that it is easily possible to lay-on the sheets also manually, if that is to be preferred in any special case. l V e 1 The grippers, or the chains to which they are attached, may be actuated by a crank gearing or the like in such a manner that the motion is slow at the commencement of the path, is then accelerated, and thereafter retarded, viz. when the sheet approaches the end of its path so that the speed of the sheet, at the end of itspath, is retarded to zero when. the front edge of the sheet contacts with the laying-on marks. There is, therefore, no upset-ting or jumping up of the sheet at said marks and an invariably correct con-tact is warranted. a l

The invention is illustrated diagrammatically and by way of example on the accompanying drawings on which Figure. l is a vertical longitudinal section through a feeding device designed ure 4 is a side-view of a gearing usedin connection with the machine, this gearing being located below the righth'and-end of Fig. 1.

0n the drawings, 1 (Figs. 1 and 3) denotes the impression cylinder, in front of which is located thelaying-on table 2. 2) denotes one of the sheets to be printed. The sheets are taken off singly by means of suckers 3 from a pile'tlocated counter to the cylinder I, i. e. at the other end of the table 2, and each sheet when having been placed upon the table is seized by grippers 5 which extend upwardly from below, through slots 22 provided in the table 2, and is'conducted along over said table, as in Fig. 1. At the other end of the table, that is to say, at the end adjacent to the impression cylinder I, there are abutment members or laying-on marks 6 attached tooscillating feeding grippers l of known construction; these grippers have cheeks 8 which seize the arriving sheet after it has been adjusted and straightened whereupon said grippers l convey the sheet to the cylinder I.

For moving the grippers over the laying-on table the following mechanism is provided:

In the frame 9 of the machine is supported, below the table 2, a shaft In (Figs. 1 and 4) on which two arms H are freely turnable. These arms are connected with one another by a transverse rod l2 connected at each end with a toggle-joint lever l3, l4 (Figs. 1 and 2). The arms i l of these levers are aiiixed to a transverse shaft i5 which is temporarily turned by eccentrics or equivalent members (not shown) whereby the frame formed by the arms I i and the transverse rod I2 is caused to oscillate in vertical direction.

Two chain-wheels 16 (Fig. 1) are secured to the shaft Ill, and counter thereto freely turnable chain-wheels l8 (Figs. 1 and 2) are located upon pivots l'l provided at the free ends of the arms l i, viz. adjacent to the impression cylinder i. These chain-wheels it are connected with the chainwheels l6 by two endless chains I9 by which the grippers 5 are moved. There are, in the constructional form shown by way of example, four grippers 5 attached to a transverse ledge 29 (Fig. 2) which is connected with said two chains l9. Each gripper consists of a body member 5 and of a seizing member 5 which is subjected to the pull of a helical tensile spring '2! so that this member 5 can adjust itself automatically to the thickness of the sheets, whichever that thickness may be; the grippers, or their members 5 respectively, are independent from one another, as appears from Fig. 2.

The table 2 is provided with longitudinal slots 22 through which the grippers extend from below to above, whereby they are placed in the position to seize the sheets and pull them along over the table.

Supposing, the grippers have seized a sheet taken off from the pile 4 by the suckers 3 and the grippers driven by the chains [9 draw that sheet along over the table to the laying-on marks 6. The arms H are during that time in the position shown in Fig. 1, that is to say, in their lifted position in which they are held by the toggle-joint levers l3, M.

The shaft of every gripping member 5 which extends through the appertaining gripper body is provided below this body with a roll 23 which cooperates with an oblique cam 24 attached to a rod 25 carried by the pivots ll (Fig. 2). The roll 23 contacts with said cam when the gripper has arrived at the end of its path where the sheet contacts with the laying-on marks. The oblique cam 24 opens the gripper (this is true of all grippers pertaining to one ledge 20) whereby the gripper is disengaged from the sheet. As soon as this has taken place, the shaft I5 is turned whereby also the toggle-joint lever arms !3, M are turned, in consequence whereof the arms II are lowered. The extent of this downward motion is such that the grippers concerned are moved to below the table 2, as in Fig. 3. When they have arrived in this position they are moved rearwardly, in the direction to the pile 4.

While the sheet is further conveyed to the impression cylinder i, the shaft I5v is again turned, but in the other direction, so that the arms I I are again lifted, together with the traverse 26 and the grippers 5, 5 The movements are so timed that the grippers are again moved upwardly so as to appear above the table 2 when the sheet mentioned has cleared the table. When the grippers 5, 5 have arrived at the end where there is the pile 4 they are again in the position to seize the next sheet that has been taken off from the pile by the suckers 3.

On the shaft I0 is a sleeve 21 (Fig. 1) from which project forth a plurality of arm-shaped cams 26, and said sleeve has, furthermore, an arm 28 connected by a link 29 with a lever 39 which is temporarily moved upwardly and down wardly by an eccentric (not shown) or an equivalent member, whereby also the arms or earns 25 are correspondingly moved. While the grippers 5, E are moved back into their initial position, as just described, the earns 26 are in their lifted position which is shown in Fig. 1. When the grippers arrive at the end of that path or, more precisely, shortly before, they are opened in order to be able to seize the next sheet, this opening being effected by the rolls 23 getting upon the earns 26, and when the opened grippers have arrived over the rim of the sheet now concerned the cams 26 are lowered by the members 28, 29, 39 whereby the grippers are closed by the springs 22! so as to take hold of that sheet. Now this sheet is conveyed to the impression cylinder, as has already been described.

Reciprocating the gripper chains 19 is effected by the following mechanism: On the shaft i9 is a pinion 3! (Fig. 4) which meshes with a cog-wheel 32 connected with another pinion 33 meshing with a toothed sector 34 connected by a link 35 with a crank disk 21 secured to a shaft 36. The sector 34- is moved one time up and down when the disk 37 makes one revolution, and the respective movement is transmitted to the gripper chains l9 by the members 33, 32, 3|, l0 and 56 (the chain-wheels, Fig. 1, righthand end), the movements being so timed that the chains i9 are moved in the one direction when the sector 34 is being moved upwardly, and are moved in the other direction when the sector is being moved downwardly, as will be clear without a more detailed description.

Making use of a crank drive (as in Fig. 4, or similarly thereto) for the gripper chains i9 presents the advantage that at the commencement of their path the grippers are moved slowly, the speed then accelerating by and by until a certain maximum has been attained. Thereafter the reverse takes place so that the sheets arrive at the laying-on members 6 with a speed that is nearly zero, whereby upsetting or jumping up of the sheets is completely prevented. Particular means for reducing the speed of the sheet shortly before they arrive at said marks can, thus, be dispensed with.

I wish it to be understood that I do not limit myself just to that one constructional form illustrated in the drawings merely by way of example. It is, for instance, possible to design the machine in such a manner that the grippers run round periodically always in the same direction; in this case several groups of grippers are required and the mechanism will be a little more complicated. Such a constructional form will be suited especially for larger sizes of sheets, whereas that shown is intended especially for smaller ones.

I claim:

1. In a cylinder printing press in combination with the impression cylinder, the oscillating feeding grippers, and a laying-on table, of chains located below said table, grippers connected to said chains, slots in said table, said grippers adapted to extend upwardly through said slots and to seize the sheet to be fed, means to drive said chains, so that said grippers move along in said slots and draw the sheet to be printed to said oscillating feeding grippers, means for withdrawing the grippers to below the table at one end of their path and for lifting them into operative position at the other end of their path, and means for opening the grippers at the first-mentioned and closing them at the other end, also these means being located below the said table.

2. In a cylinder printing press in combination with the impression cylinder, the oscillating feeding grippers and a laying-on table, of chains located below said table, grippers connected to said chains, slots in said table, said grippers adapted to extend upwardly through said slots and to seize the sheet to be fed, a crank gearing for driving said chains so that said grippers move along in said slots and draw the sheet to be printed to said oscillating feeding grippers, said crank gearing being adapted to drive said chains in such a manner that the speed of the chains is practically zero at both ends of the path of said grippers, means for withdrawing the grippers to below the table at one end of their path and for lifting them into operative position at the other end of their path, and means for opening the grippers atthe first-mentioned and closing them at the other end, also these means being located below the said table.

3. In a cylinder printing press in combination with the impression cylinder, the oscillating feeding grippers and a laying-on table, of chains 10- cated below said table, chain-wheels supporting said chains, grippers connected to said chains, slots in said table, said grippers adapted to extend upwardly through said slots and to seize the sheet to be fed, means to drive said chains so that said grippers move along in said slots and draw the sheet to be printed to said oscillating feeding grippers, a shaft connected with the chain-wheels at one end of the gripper path, a frame supported on said shaft and adapted to oscillate vertically so as to lift and lower the chain-wheels arranged at the other end of the gripper path, toggle levers connected with said frame and means for actuating said toggle levers.

4. In a cylinder printing press in combination with the impression cylinder, the oscillating feeding grippers and a laying-on table, of chains located below said table, chain-wheels supporting said chains, grippers connected to said chains, slots in said table, said grippers adapted to extend upwardly through said slots and to seize the sheet to be fed, a shaft connected with the chain-wheels at one end of the gripper path, a crank gearing for driving said shaft alternately in the one and the other direction, a frame supported on said shaft and adapted to oscillate vertically so as to withdraw the grippers to below the table at one end of their path and to lift them into operative position at the other end of their path, toggle levers connected with said frame, and means for actuating said levers.

RUDOLF STUSSI. 

